Ectopic pregnancy does not usually occur after taking birth control pills. If birth control pills are taken according to the instructions, the chances of causing pregnancy are very low and ectopic pregnancy rarely occurs. Contraceptive pills include estrogen and progestin combination, progestin mono-preparation and non-steroidal drugs, etc. Contraceptive pills can achieve the purpose of contraception by changing cervical mucus, inhibiting ovulation and preventing the fertilized egg from being laid. Contraceptive pills are generally divided into long-acting pills, short-acting pills and emergency pills, and the mechanism of contraception differs from pill to pill. Short-acting and long-acting contraceptives generally do not fail as long as they are taken according to instructions and not missed.